It helps to have a surplus of optimism in running against Mikulski, the two-term incumbent who trounced her Republican challenger with 71 percent of the vote in 1992 and has already amassed a $1.6 million campaign war chest for this time around.

Mikulski's strength helps account for the dearth of well-known candidates looking to challenge her this year. Ten Republicans and three Democrats have filed to appear on the Sept. 15 primary ballot alongside Mikulski, most of them virtual unknowns. The four candidates who have been visibly campaigning for the GOP nomination -- Wayman, Baltimore contractor Thomas Scott, Finksburg physician Michael Gloth and Baltimore lawyer George Liebmann -- are all making their first bids for public office.

Even so, some of the candidates have infused some provocative ideas into the race. And some are quick to put an upbeat spin on their admittedly long odds.

"I hope that going around the state talking about these things will have an effect," Liebmann said after a sparsely attended news conference recently. "Even if my campaign goes nowhere."

Liebmann and some of Mikulski's other opponents charge that the 62-year-old Baltimore native is too liberal even for the historically Democratic state, that she is too entrenched on Capitol Hill and that her attention to constituent services has slackened.

Mikulski's campaign manager, Ann R. Beser, said the senator will decline to respond to statements made by her Republican challengers until after the primary.

Beser said Mikulski intends to run hard, despite the low wattage of this year's opposition. "An easy campaign is not the same as no campaign," she said. "Any challenge calls for the need to campaign, and to get our message to the voters."

Of all the long shots in the race, Liebmann, 59, is probably the best known within the state political establishment. He was an assistant state attorney general and an aide to then-Gov. Harry R. Hughes (D).

While the other candidates mostly echo themes sounded by the Republican congressional leadership, Liebmann -- the author of several texts on Maryland law and local governments -- aims in slightly different directions, with some of the more detailed and policy-specific proposals of the campaign.

Earlier this month, he published a detailed, 34-page study that assessed and criticized teachers union contracts in all 24 Maryland school districts. The report, released by the Calvert Institute, a conservative think tank, recommended a greater emphasis on merit pay and suggested that every school should have its own governing board. He also made a scholarly argument in favor of school drug testing.

Except for some recommendations to lessen federal involvement in local school systems, the lengthy report barely touched on issues that Liebmann would address as a senator. He explained that he authored the study long before choosing to run for the Senate but that he thinks "political candidates and elected officials can be change agents" in public policy.

Liebmann wants to make several changes to the tax code, reducing the income tax burden on lower and middle-income earners, expanding the family tax credit and increasing excise taxes. He also proposes that the federal government encourage a novel form of day care -- a European practice in which a paid caregiver is assisted by three or four parent aides.

Gloth, 42, has received some attention from Republican leaders for having raised the most money -- about $25,000 this year. A boyish and articulate geriatrics specialist, Gloth claims he can win non-GOP voters as a doctor who makes house calls in Mikulski's old congressional district.

He criticizes Mikulski for voting against a ban on certain late-term abortions but says he would not support federal legislation otherwise prohibiting abortion. Drawing on his medical experience, he rails against the administrative burden that Medicare places on physicians and says he would call for Senate hearings on the Health Care Finance Administration.

Wayman, 51, who owns a software development firm in Ellicott City, said he entered the Senate race because the local races in Carroll County, where he lives, already had been held or were being pursued by strong Republican candidates.

He advocates that the current tax code be replaced with a flat tax, and says he would push for greater spending on national security and defense, citing the potential nuclear arms race between India and Pakistan.

He also recommends an overhaul of the Social Security system. "The only way we are going to be able to honor our commitments is to leave the current system in place and start to privatize it," he said. "We can't disregard our obligations."

Scott, 52, a Baltimore native and general contractor, calls for abolition of the Internal Revenue Service but says it should be replaced by a national sales tax. He said he would like to abolish the U.S. Department of Education, which he blames for imposing burdensome regulations on public schools.

Scott pledges to abide by his own term limit in order to break through the culture of entrenchment he believes pervades Washington. After two terms, he said, he would step down. "At the end of that period of time, you begin to become part of the establishment," he said. "That's where the problem comes in."

Although these four men are the only ones who appear to be actively campaigning, some Republican leaders say that their low profiles may doom them all in the end. One strategist suggested that retired Timonium surgeon Ross Z. Pierpont -- the veteran of more than a dozen unsuccessful campaigns, including several bids for governor -- could win a plurality simply on the strength of his vaguely familiar name.

Meanwhile, Bradlyn McClanahan, of Annapolis, another perennial candidate, boasts of having the greatest name recognition in the GOP field -- 15 percent, according to a recent Mason-Dixon poll.

Others appearing on the Republican ballot are Barry Steve Asbury, of Parkville; Howard David Greyber, of Potomac; John Stafford, of Laurel; and John Taylor, of Crofton.